1. Field of the Invention
The present invention relates to an electrical connection portion whose electrode is fixed to an apparatus main body, and to an adapter type endoscope having the electrical connection portion.
2. Description of the Related Art
Conventionally, endoscope apparatuses have been widely used in medical fields and industrial fields. The observation object of the endoscope is the inside of a living body, a pipe, and the like. Therefore, when an endoscopic examination is performed, a light source for illuminating the observation object is needed. In a common endoscope apparatus, a light source apparatus which supplies illumination light is prepared as an external apparatus of the endoscope. The illumination light emitted by the light source apparatus is supplied to a light guide provided in an insertion portion of the endoscope, and is transmitted to the distal end portion of the insertion portion via the light guide. Then, the illumination light is emitted towards the observation object from an illumination window arranged at the insertion portion distal end portion.
In recent years, there is proposed an endoscope which, instead of transmitting the illumination light emitted by the light source apparatus to the distal end portion of the insertion portion via the light guide, is configured to have a light emitting device such as a light emitting diode (hereinafter abbreviated as LED) provided at the distal end portion of the insertion portion, and to illuminate the observation object with the light emitted by the light emitting device. In the case where the endoscope having the light emitting device provided at the distal end portion, is configured such that an image of the observation object illuminated by the light emitting device is picked up by an image pickup device, an electrical cable extended from the image pickup device, and an electrical cable for supplying electric power to the light emitting device are inserted in the insertion portion. This makes it possible to realize an endoscope having a small diameter and a simple configuration, and having a high performance.
For example, there is disclosed in Japanese Patent Laid-Open No. 2005-027851 (hereinafter described as document 1) an endoscope which enables excellent observation to be performed for a long time by preventing the trouble caused by the heat generated from an LED arranged in the insertion portion distal end portion. In FIG. 9 or the like of document 1, there is shown an endoscope in which the LED is provided in an adapter, and the adapter can be detachably attached to the distal end portion of the endoscope. In the endoscope, when the adapter main body is attached to the distal end rigid portion, a projection electrode provided in the plate electrode is electrically connected to a contact pin of an illumination electrode. Further, there is disclosed in Japanese Patent Laid-Open No. 2005-110879 (hereinafter described as document 2) an endoscope which makes it possible to perform excellent observation based on a desired optical property under illumination of an LED for a long time, by arranging a distal end adapter provided with the LED. These endoscopes are desired to have a further reduced diameter.
In the endoscope as disclosed in the documents 1 and 2, a pair of electrical contacts for supplying electric power are prepared for LED illumination, and the pair of electrical contacts are provided in a mutually facing positional relationship so as to be separated from each other by a predetermined distance.
Thus, in the adapter shown in FIG. 9 of document 1, a work to electrically connect an electric wire which is not stiff and formed in a short length, to the LED illumination side, and a work to electrically connect the electric wire to the plate electrode side, are respectively performed two times. The work is a technique needing skill. Further, the adapter shown in FIG. 13(a) of document 1, is configured such that a leaf spring-like curved portion provided at the proximal end portion of the electrode projecting from the LED illumination side is brought into electrical contact with a tubular illumination pipe electrode by the urging force of the spring. In the endoscope configured in this way, a clearance is provided in each electrode recessed portion in consideration of the spring property of the curved portion. On the other hand, in the endoscope shown in FIG. 2 and FIG. 9(a) to FIG. 9(d) of document 2, an insulating portion having a thickness necessary for insulation is independently provided around each adapter terminal.